A module of a binary structure \(R:=(V,(\rho _{i})_{i\in I})\) , where each \(\rho _i\)  is a binary relation on \(V\) , is a module of \(\rho _i\) 
for all \(i\in I\) . The empty set, the singletons in \(V\)  and the whole set \(V\)  are modules of \(R\)  and are said to be trivial. A module is proper if it is distinct of \(V\) . A binary relational structure is prime (or indecomposable) if it has no nontrivial modules. Incidentally, a relational structure on at most two elements is prime. A module is strong if it is nonempty and it overlaps no module [1]}. The singletons and the whole set are strong and are called trivial. A component of \(R\)  is a maximal (with respect to set inclusion) proper strong module of \(R\) .
